Plural fluid mixing and spray apparatus

ABSTRACT

An improved airless spray apparatus incorporating and improving on the mixing valve of U.S. Pat. No. 3,490,493 (C. A. Eversman, Volume and Mixture Controllable Valve Assembly, Filed Nov. 30, 1966) Resulting in a light weight versatile spray gun for mixing and spraying plural fluid components such as polyesters, foam or the like, which has as the mixing valve ensemble, a valve cylinder having one pair of circumferentially spaced inlet ports communicating with a first and second source of fluid and a second pair of circumferentially spaced inlet ports communicating with a third source fluid, and a cylindrical valve piston disposed within the valve cylinder for rotational movement therein. The peripheral inner wall of the valve cylinder and the peripheral wall of the outer wall of the valve piston being in fluid tight relation and the valve piston having a control handle for controlled limited rotation to selectively permit and direct the flow, mixing and dispensing of the first and second, or third, fluid through the valve piston.

[22] Filed:

Krueger [541 PLURAL FLUID MIXING AND SPRAY APPARATUS [76]' Inventor: Wallace F. Krueger, 4401 Merriweather Avenue, Toledo, Ohio June 19, 1970 [21] Appl. No.: 47,814

[52] U.S. Cl ..239/4l5, 239/527 [51] Int. Cl ..F23d 13/38 [58] Field of Search ..239/526, 527,528, 414, 415,

239/4l6.l; l37/625.17

[56] References Cited UNITED STATES PATENTS 1,605,259 11/1926 Mersch ..239/4l5 X 2,989,242 6/1961 Turak ..239/4l4 X 2,372,305 3/1945 Walker ..239/41 5 X 2,910,248 10/1959 Kueter et al ..239/415 2,969,923 1/1961 Fremion ..239/4l5 3,490,493 1/1970 Eversman ..l37/625.l7

Primary Examiner-Lloyd L. King Attorney-Joseph R. Scalzo 1 Jan. 2,1973

[ ABSTRACT An improved airless spray apparatus incorporating and improving on the mixing valve of U.S. Pat. No. 3,490,493 (C. A. Eversman, Volume and Mixture Controllable Valve Assembly, Filed Nov. 30, 1966) Resulting in a light weight versatile spray gun for mixing and spraying plural fluid components such as polyesters, foam or the like, which has as the mixing valve ensemble, a valve cylinder having one pair of circumferentially spaced inlet ports communicating with a first and second source of fluid and a second pair of circumferentially spaced inlet ports communicating with a third source fluid, and a cylindrical valve piston disposed within the valve cylinder for rotational movement therein. The peripheral inner wall of the valve cylinder and the: peripheral wall of the outer wall of the valve piston being in fluid tight relation and the valve piston having a control handle for controlled limited rotation to selectively permit and direct the flow, mixing and dispensing of the first and second, or third, fluid through the valve piston.

4 Claims, 14 Drawing Figures PATENTEDJM 2 I975 SHEU 1 BF 6 INVENTOR.

BY WALL/ Z5 F. KRUEGER ATTORN EY PATENTEDJAH 2mm 3.708.123

sum 3 or 6 INVENTOR WALLACE F. KRUEGER rfY ATTORNEY PATENTEDJAN 219% 3,708,123

SHEET 0F 6 FIG. 7 1

INVENTOR. WALLACE F. KRUEGER ATTORNEY PATENTED JAN 2 mg I NNNN o R WALLACE E KRUEGER ATTORNEY PATENTED 21975 3,708,123

SHEET 5 BF 6 INVENTOR. WALLACE F. KRUEGER ATTORNEY PLURAL FLUID MIXING AND SPRAY APPARATUS The present invention relates to a vastly improved and useful airless spray apparatus and more particularly to a completely new plural fluid control and mixing spray gun which among other things incorporates a vastly new and novel mixing valve mechanism which increases the sealing capabilities as pressures are increased which is a critically important improvement in spraying plural fluid components which must remain separated until mixed.

One of the primary objectives of this invention is to produce a new and novel plural fluid control and mixing spray gun that has an improved mixing valve mechanism and is more effective than any heretofore produced and completely reliable in operation, yet simple in design and construction, easy to operate, easy to clean and maintain in effecient operating condition, easy to assemble or tear down with minimum of and easily accessable parts, light in weight and designed for one hand handling, making the cost of production and repair and replacement more favorable than those of the comparable present art, and safer to operate at higher as well as lower pressures normally required in the art.

Other objects and advantages of the invention will be clearly apparent from the following detailed description of the embodiment of the invention and the accompanying drawings in which:

FIG. 1 is an exploded perspective view of the spray apparatus looking downwardly at the rearand left hand side depicting the essential parts of the spray apparatus.

FIG. 2 is an exploded perspective view of the spray apparatus looking downwardly at the front and right hand side depicting the essential parts of the spray apparatus.

FIG. 3 is a horizontal cross sectional view of the spray apparatus showing theflow pattern of the first and second source fluids with the valve assembly in such position as to restrict the flow of the first and second source fluids to the central mixing chamber.

FIG. 4 is a vertical cross sectional view of the spray apparatus showing the flow pattern of the third source fluid with the valve assembly in such a position as to permit the flow of the third source fluid to the central mixing chamber and outlet line.

FIG. 5 is a horizontal cross sectional view of the spray apparatus similar to FIG. 3 showing the flow pattern of the first and second source fluids but with the distinction from FIG. 3 that the valve assembly is in such a position as to permit flow of the first and second source materials to the central mixing chamber and outlet line. FIG. 6 is a vertical cross sectional view of the spray apparatus similar to FIG. 4 showing the flow pattern of the third source fluid but the valve assembly in such a position as to restrict the flow of the third source fluid to the central mixing chamber.

FIG. 7 is a cross sectional perspective view of the spray apparatus looking doenwardly at the top and left hand side depicting in detail the flow pattern through the spray apparatus body, the cylinder and the piston portions of the valve assembly, the central mixing chamber, and outlet line.

FIG. 8 A is a cross sectional front end view of the valve assembly showing relative cylinder and piston positioning when the spray apparatus is in the off position;

FIG. 8 B is a cross sectional front end view of, the

valve assembly showing relative cylinder and piston positioning when the spray apparatus is in the third source material on"positi0.n. e I

FIG. 8 C is a cross sectional front end view of the valve assembly showing relative cylinderand piston positioning when the spray apparatus is in the first and second source material on position.

FIG. 9 A is a rear end view of the spray apparatus showing the control handle positioning when the spray apparatus is in the "off position.

FIG. 9 B is a rear end view of the spray apparatus showing the control handle positioning when the spray apparatus is in the third source material on position.

FIG. 9 C is a rear end view of the spray apparatus showing the control handle positioning when the spray apparatus is in the first and second source material on position.

FIG. 10 is a side elevational view of the spray apparatus depicting its sleek design.

Referring to the accompanying drawings, the plural fluid control and mixing spray apparatus is shown generally by numeral 11 and clearly depicts the grip handle 12, the safety trigger 13, the control handle 14, and the cast spray apparatus body 15. The control handle 14 is an extension of the central longitudinal valve piston 16, the two being connected by a pin 59 for upward rotation to permit more feasible flow control.

Three threaded bores, 17, 18, and 19 are drilled and tapped in the rear face 20 of the spray apparatus body 15 for easy insertion of fittings 21 which are connected to the solvent and material source lines, which are not shown, to permit solvent and material flow into the spray apparatus 11. The two material bores 17 and 18 are parallel to the central longitudinal valve piston 16 and each bore 17 and 18 is equidistant from the central piston 16, all three of which lie in a plane. Thesolvent bore 19 lies in a plane with-the centrallongitudinal valve piston 16 which is perpendicular to the plane formed by the central longitudinal valve piston 16 and the two material bores 17 and 18. The solvent bore 19 is approximately located the same distance from the central longitudinal valve piston. 16 as I are the two material bores 17 and 18. Therefore, if lines were.

drawn from the center of one material bore 17 to the other material bore'l8 and lines drawn from the center of the two material bores 17 and 18 to the center of the solvent bore 19, an isosceles triangle'would be formed with the sides adjacent to the solvent bore 19 vertex being equidistant and the side opposite the solvent bore 19 vertex being approximately twice the distance of the equal sides. Preferred check valves 25 and 64 are used in the material bores 17 and 18 to prevent the back-up of any material component into the pressurized source of the two component materials; these checkvalves being external to the body 15 of the spray apparatus 1 l. I The two threaded material bores 17 and 18 may typinal central mixing chamber 34. The filters 32 and 33 may be easily cleaned and this feature prevents clogging of the internal ports so that less internal cleaning is necessary.

The essential valve mechanism in the present invention consists essentially of a valve cylinder 49 having one pair of circumferentially spaced inlet material lines 62 and 63 communicating with a first and second source of fluid that must be-separated, and a second pair of circumferentially spaced inlet solvent lines 60 and 61 communicating with a third source of fluid such as a solvent or the like. Grooves 52 A and B, 56 A and B with O-ring seals 51 A and B, 55 A and B surround each of the four inlet ports 28, 29, 22, and 23 of lines 62, 63, 60, and 61. The O-ring grooves 52 A and B, 56 A and B are machined deep enough to permit increased flexing of the inner groove area under surface so that as fluid pressure is applied to this area the surface to surface seal between the cylinder inner peripheral surface 53 and the outer peripheral valve piston surface 50 is increased as the pressure increases, and the O-ring sealing capacity likewise increases thus preventing undesirable leakage or seepage at high pressure, a common failing in other mechanisms of the same purpose.

The two material bores 17 and 18 connect to the material lines 26 and 27 respectively within the spray apparatus body 15. The material lines 26 and 27 run parallel to the material bores 17 and 18 in the spray apparatus body until each material line 26 and 27 proceeds through the valve cylinder 49 to the central mixing chamber 34. At the points in the spray apparatus body 15 of the spray apparatus 11 where the material lines 26 and 27 proceed to the central mixing chamber 34, a preferred angle of approximately 135 is formed between the portion of the material lines 26 and 27 which is parallel to the axis of the central longitudinal valve piston 16 and the further extensions 35 and 36 of material lines 26 and 27 which are bored to the inlet cylinder ports 28 and 29 of the cylinder portion 49 of the valving structure 48. By boring the material lines 35 and 36 to the inlet cylinder material ports 28 and 29 of the cylinder portion 49 of the valve structure 48 at a preferred angle of approximately 135 a turbulence is created in the material components at the vertices 37 and 38 of the angles. The material components after entering the inlet cylinder ports 28 and 29 flow through the circumferentially spaced valve cylinder material lines 62 and 63 respectively. If the control handle 14 of the spray gun I] is in the material on position, as shown in FIGS. 8 C and 9 C, the valve cylinder material lines 62 and 63 meet with the internal piston lines 57 and 58 respectively and material flow is then permitted to the central mixing chamber 34 where the turbulence created at vertices 37 and 38 mentioned above insures proper mixing of the material components. The mixed material fluid is then permitted to exit from the spray apparatus 11 through the outlet line 54 bored in the central longitudinal piston 16. If the control handle 14.0f the spray apparatus 11 is in the solvent on position as shown in FIGS. 8 B and 9 B or the of position as shown in FIGS. 8 A and 9 A, material component flow is restricted to the central longitudinal valve piston because internal piston lines 57 and 58 do not line up with valve cylinder material lines 62 and 63 respectively.

The solvent bore 19 described previously, located at the bottom of the rear face 20 of the spray apparatus 1 1 is typically though not always connected to the solvent source line connectors as best portrayed in FIG. 1. A nipple 39 is threaded into the solvent bore 19 which may be typically connected to a coupling filter arrangement not shown which is similar to those filter arrangements 32 and 33 utilized in the material source line connectors. This again enables easy cleaning .of the filter and prevents most foreign matter from entering the small internal lines and mechanisms of the spray apparatus 11. The solvent bore 19 is connected to the internal solvent line 41 inside the body 15 of the spray apparatus 11 to enable the internal lines and mechanisms of the spray apparatus 11 to be solvent cleaned to prevent material build up, thereby clogging the internal lines. The internal solvent line 41 forms an angle of approximately 45 with the central axis of the solvent bore 19. The solvent line 41 extends to the central'longitudinal valve piston 16 and at the point where the two intersect, a groove 42 has been machined around the entire circumference of a circular metal sleeve 45 placed around the central longitudinal valve piston 16 to enable solvent to pass around the central longitudinal valve piston 16 and flow from the bottom portion 43 of the spray apparatus body 15 as divided by the axis of the central longitudinal valve piston 16 to the top portion 44 of the spray apparatus body 15 which enables total cleaning of internal lines and mechanisms. By cutting the groove 42 in the metal sleeve 45, solvent leakage is essentially curtailed because a tight surface to surface seal is established between the metal sleeve 45 and the spray apparatus body 15, whereby solvent is only permitted to pass around the central longitudinal valve piston 16 to the top portion 44 of the spray apparatus body 15 above the axis of the central longitudinal valve piston 16 where the solvent flow then enters the solvent line 46, a further extension of solvent line 41, which forms an angle of approximately 45 with the axis of the central longitudinal valve piston 16. The solvent line 46 extends into the top portion 44 of the spray apparatus body 15 and then, in order to clean the lines of the central longitudinal valve piston 16, solvent line 46 turns at an angle of approximately and meets cylinder portion inlet port 22 which is the point of entry to the valve cylinder solvent line 62 of the cylinder portion 49 of the valve structure 48. If the spray apparatus 11 is in the off or material on position as shown in FIGS. 8 A and 9 A, and FIGS. 8 C and 9 C respectively the solvent flow is restricted by the outer peripheral valve piston surface of the central longitudinal valve piston 16 at the point where the surface to surface seal is established between the cylinder inner peripheral surface 53 and the outer peripheral valve piston surface 50. Leakage is curtailed along the central longitudinal valve piston 16 because of the tight surface to surface seal between the cylinder inner peripheral surface portion 53 and the outer peripheral valve piston surface 50. At the point where the solvent line 46 enters the valve cylinder portion 49, leakage is prevented by an O-ring seal 55A placed in the elliptical groove 56A machined into the outside surface area of the valve cylinder portion 49. This seal prevents leakage along the outside circumferential surface area of the valve cylinder portion 49. If the spray apparatus 11 is in the solvent on" position as shown in FIGS. 8 B and 9 B, solvent is permitted to flow into the internal piston line 57 because the internal piston line 57 is rotated to meet the valve cylinder solvent line 60. The internal piston line 57 is rotated to meet the valve cylinder solvent line 60. The internal piston line 57 is enclosed in the central longitudinal valve piston 16 so that the solvent may flow to the central mixing chamber 34 through the internal piston line 57, which by rotation may carry either solvent or material, to purge any material residue from the internal piston line 57 and the central mixing chamber 34. After flow through the central Y mixing chamber 34 the solvent purge fluid is ejected through the same outlet line 54 as are the two mixed component materials so that cleaning of the outlet line 54 is also permitted.

At the point of solvent entry into the internal line 41 of the spray apparatus 11 where the inlet solvent bore 19 and the internal solvent line 41 intersect, the solvent may either proceed through the upper portion 44 of the spray apparatus 11 as described above or may proceed through the lower portion 43 of the spray apparatus 11.

, The internal solvent line 41 also extends in the opposite direction from that portion of the solvent line 41 which extends to the central longitudinal valve piston 16. This portion of the internal solvent line 41 extends to the lower portion 43 of the spray apparatus body and then, in order to clean the lines of the central longitudinal valve piston 16, the solvent line 41 turns at a preferred angle of approximately 90 and meets the cylinder portion inlet port 23 which is the point of entry to the valve cylinder solvent line 63 of the valve cylinder portion 49. The solvent line 41 enters the bottom of the valve cylinder portion 49 in a similar manner as the solvent line 46 enters the top portion of the cylinder valve portion 49. An O-ring seal 55B placed in the machined ellipitical groove 56B prevents leakage along the outside circumferential surface area of the valve cylinder portion 49 similar to that of the O-ring seal 55A placed in the elliptical groove 56A in the top of the valve cylinder portion 49. Surface to surface seal between the valve cylinder inner peripheral surface 53 and the outer peripheral valve piston surface 50 is the same as with the top valve cylinder solvent line 60 since it is the same central longitudinal valve piston 16 and valve cylinder portion 49 but at a different point of contact. If the spray apparatus 11 is in the solvent on position as shown in FIGS. 8 B and 9 B, solvent is permitted to flow through the valve cylinder solvent line 61 to the internal piston line 58, which by rotation of the central longitudinal valve piston 16 may carry either solvent or a material component. This piston line 58 extends to the central mixing chamber 34. By solvent flow through the internal piston line 58, line 58 it self may be cleaned of any material residue and then so may the central mixing chamber 34 since this internal piston line 58 proceeds to the central mixing chamber 34. At the central mixing chamber 34 the internal piston lines 57 and 58 intersect, and when the spray apparatus 11 is in the solvent on position, solvent is forced through both internal piston lines 57 and 58 and is permitted then, to exit from the spray apparatus 11 through the same outlet line 54 as the mixed material the outlet line54.

The control handle 14 of the spray apparatus 11 is a significant part of the subject invention since this control handle 14, by being connected to the central longitudinal valve piston 16 controls whether solvent flow, material flow, or no flow is permitted to the central mixing chamber 34. A connector pin 59 permits the control handle 14 to be connected to the central longitudinal valve piston 16. A detent arrangement 24 permits the control handle 14 to be partially locked in an upright position perpendicular to the central longitudinal valve piston 16 or if the control handle 14 is rotated approximately 90 around the connector pin 59 the control handle 14 may be partially locked coaxial with the central longitudinal valve piston 16. With the control handle 14 in the upright position as shown in FIG. 9 A, the internal piston lines 57 and 58 do not meet with either the valve cylinder material lines 62 and 63 or the valve cylinder solvent lines 60 and 61. If the control handle 14 is rotated 45 to the left as viewed from the rear face 20 of the spray apparatus 11 as shown in FIG. 9 B, then the internal valve piston lines 57 and 58 are permitted to meet the valve cylinder solvent lines 60 and 61 respectively. If, from the of upright position the control handle 14 is rotated approximately 45 to the right as shown in FIG. 9 C, the valve cylinder material lines 62 and 63 are permitted to meet the internal piston lines 57 and 58 so that the two material components may flow to the central mixing chamber 34.

The control handle 14 as best viewed in FIGS. 9 is 0 such construction and size that it may remain connected to the central longitudinal valve piston 16 when taking the spray apparatus 11 apart, as the central longitudinal valve piston 16 is pulled from the spray apparatus body 15. Bore 67 in the rear face 20 of the spray apparatus body 15 which is bored equidistant from the material bore 17 and 18 and the solvent bore 19 is of sufficient size to allow the central longitudinal valve piston 16 to pass through it and is of such tolerance in relation to the central longitudinal valve piston 16 that the spray apparatus body 15 forming the outside circumferential surface of the cylindrical shaped bore 67 fits tightly around the central longitudinal. piston 16. The control handle 14 is necessarily then of a lesser diameter at all points of the control handle 14 than the diameter of the bore 67 so that it may be removed through the bore 67 by being revolved approximately around pin 59 so that it is coaxial with the central longitudinal valve piston 16 and can-be pulled through the spray apparatus body 15 passing through bore 67. 1

Referring now to FIGS. 1 and 2, the structural parts of the spray apparatus 11 combine as shown. The grip handle 12 and the spray apparatus body 15 are preferrably cast as one piece with the internal lines in the spray apparatus body 15 being machined after the casting process. The valve cylinder portion 49 fits circumferentially around the central longitudinal valve piston 16 in a position that permits the valve cylinder solvent lines 60 and 61 as best viewed in FIGS. 4 and 6 and the valve cylinder material lines 62 and 63 as best viewed in FIGS. 3 and 5 to meet the internal valve piston lines 57 and 58 by a simple rotation of the central logitudinal valve piston 16. The central longitudinal valve piston 16 with the valve cylinder 49 fit inside the spray; apparatus body 15 in such a positionthat the internal lines 35, 36, 41, and 46 of the spray apparatus body meet the valve cylinder material and solvent lines 62, 63, 60 and 61, as can be best viewed in FIGS. 3, 4, 5, and 6. A pin 40 fits through the central longitudinal valve piston 16 so that it may be placed in the pin channels 65 and 66 of the valve cylinder portion 49 to restrict rotation of the central longitudinal valve piston 16 to approximately 45 to the right and left of the off position as shown in FIGS. 8 and 9. This rotation of 45 to the right and left is sufficient to place the central longitudinal valve piston 16 in the material flow on and the solvent on positions respectively.

The grip handle 12 is of convenient shape and size to permit functional gripping by both right and left handed operators. The grip handle 12 is hollow to reduce the weight of the total spray apparatus 11 and to permit more feasible operation and movement by the operator of the spray apparatus 11. A groove 70 is machined into the grip handle 12 to permit the introduction of a safety trigger 13 to prevent the control handle 14 from accidently slipping out of the off position. The safety trigger 13 is attached to the spray apparatus body 15 by a pin 69 which is inserted into a bore 71 of the spray apparatus body 15 coincident with a bore 72 in the safety trigger 13. By placing the pin 69 through bore 71 of the spray apparatus body 15 on one side of groove 70 machined in the grip handle 12, then through bore 72 of the safety trigger l3, and through bore 71 on the opposite side of groove 70, the safety trigger 13 is firmly attached to the spray apparatus body 15. A slot 73 is machined into the safety trigger l3 and a slot 74 is machined into the top portion of the grip handle 12 behind the groove 70. One end of the spring 68 is placed in groove 73 and the other end of spring'68 in groove 74 to create sufficient tension to force the detent tab 75 into the detent groove 76 as best seen in FIG. 1 when the control handle 14 is in the off position. If the safety trigger 13 is pulled toward the grip handle 12, the control handle 14 which is connected to the central longitudinal valve piston 16 may be rotated from the off position since the detent tab 75 is no longer confined to the detent groove 76 which prohibits rotation of the central longitudinal piston 16.

Threads 77 having been machined into the spray apparatus body 15 permit insertion of the tapered threaded disk 78 which holdsthe valve cylinder 49, and the central longitudinal piston 16 within the spray apparatus body 15. Bores 79 have been machined around the outside circumference of the tapered threaded disk 78 for the insertion of a spanner wrench to permit feasible threading and unthreading procedures. Bore 81, machined through the tapered threaded disk 78 permits the tapered threaded disk 78 to be positioned circumferentially around the central longitudinal valve piston 16. The smooth machined face 83 of another tapered disk 82 is placed flush to the smooth machined face 80 of the tapered threaded disk 78. Bore 84 permits the tapered disk 82 to fit circumferentially around the central longitudinal piston 16. The tapered disk 82 is not threaded so it is therefore attached to the central longitudinal valve piston 16 by a set screw 85. A threaded bore 86 for insertion of the set screw 85 is machined between groove 76 and the machined bore 84so that the set screw 85 may lock against the central longitudinal valve piston 16. Therefore, whenever the control handle 14 is in the off position the detent tab fits within groove 76 of the tapered disk 82. When the safety trigger 13 is pulled back, the control handle 14 may be rotated to either the material on or sol;- vent on positions and the tapered disk 82 will also rotate so that the detenttab 75 will not slip back into groove 76. The threaded end 87 of the central longitudinal valve piston 16 is used to attach a typical threaded spray nozzle tip arrangement 88 for spray dispensing.

It will be understood that what has been described is a preferred embodiment of the invention; however changes in the embodiment may be made while remaining within the perview of the present invention.

Having described in full the present invention, what is now claimed is:

1 In a spray apparatus of the class described for mixing and spraying a plural fluid mixing valve structure comprising:

a valve cylinder having one pair of circumferentially spaced inlet ports communicating with a first and second source of fluid, and a second pair of circumferentially spaced inlet ports communicating with a third source fluid;

a cylindrical valve piston disposed within said valve cylinder for rotational movement therein, the

peripheral inner wall of said valve cylinder and the peripheral outer wall of said valve piston being in fluid-tight relation, said valve piston having an outlet port at one end thereof and a pair of circumferentially spaced inlet ports in the cylindrical wall thereof and said grooves are formed on the outer peripheral surface of said valve cylinder surrounding the inlet ports thereof, for including O-ring seals at least partially disposed within each of said grooves, and wherein said grooves which are formed on the peripheral surface 'of said valve cylinder are of such relative depth to the wall thickness of said valve cylinder so as to result in slight inward deflection of the surface area within said grooves when fluid pressure is applied to the surface within said grooves, thus causing a greater sealing action between the inner peripheral surface of the valve cylinder and the outer peripheral surface of the valve piston; a central longitudinal hollow bore within said valve piston terminating at one end with said outlet port and at the other end with a pair of hollow passages connecting with said pair of circumferentially spaced inlet ports; means for limiting the rotational movement of said valve piston relative to said valve cylinder; and

manual actuator affixed to said valve piston whereby rotational movement of said valve piston can be affected to selectively position the pair of inlet ports thereof relative to the respective pair of inlet ports of the first and second source of fluid or of the pair of inlet ports of the third source of fluid of said valve cylinder. 2. In a spray apparatus of the class described for mixing and spraying plural fluids;

a fluid mixing valve as defined in claim 1 wherein said manual actuator affixed to said cylindrical valve piston comprises a handle connected .to-one end'of said cylindrical valve piston by means of a pin and detent mechanism, so as to permit lifting periphery thereof, a sleeve surrounding one portion of 10 said cylindrical valve piston, a groove on the outer peripheral surface of said sleeve to transfer the third fluid, connecting passages from said sleeve groove to each of said cylindrical valve piston ports, thus permitting a single solvent third fluid inlet to transfer solvent for cleaning purposes to both material inlet ports of said cylindrical valve piston.

4. A spray apparatus for mixing and spraying plural fluids containing the fluid mixing valve and actuating means as described in claim 1 which consists of a spray apparatus body to contain said mixing valve, a grip handle disposed beneath and connected to said body,

trigger mechanism on said grip handle for releaseably locking said mixing valve to prevent or permit rotation of said cylindrical valve piston, a dispensing nozzle removeably attached to the outlet end portion of said cylindrical valve piston to dispense mixed fluids, and suitable adapters and connecting lines'to carry the fluids to the spray apparatus. 

1. In a spray apparatus of the class described for mixing and spraying a plural fluid mixing valve structure comprising: a valve cylinder having one pair of circumferentially spaced inlet ports communicating with a first and second source of fluid, and a second pair of circumferentially spaced inlet ports communicating with a third source fluid; a cylindrical valve piston disposed within said valve cylinder for rotational movement therein, the peripheral inner wall of said valve cylinder and the peripheral outer wall of said valve piston being in fluid-tight relation, said valve piston having an outlet port at one end thereof and a pair of circumferentially spaced inlet ports in the cylindrical wall thereof and said grooves are formed on the outer peripheral surface of said valve cylinder surrounding the inlet ports thereof, for including O-ring seals at least partially disposed within each of said grooves, and wherein said grooves which are formed on the peripheral surface of said valve cylinder are of such relative depth to the wall thickness of said valve cylinder so as to result in slight inward deflection of the surface area within said grooves when fluid pressure is applied to the surface within said grooves, thus causing a greater sealing action between the inner peripheral surface of the valve cylinder and the outer peripheral surface of the valve piston; a central longitudinal hollow bore within said valve piston terminating at one end with said outlet port and at the other end with a pair of hollow passages connecting with said pair of circumferentially spaced inlet ports; means for limiting the rotational movement of said valve piston relative to said valve cylinder; and a manual actuator affixed to said valve piston whereby rotational movement of said valve piston can be affected to selectively position the pair of inlet ports thereof relative to the respective pair of inlet ports of the first and second source of fluid or of the pair of inlet ports of the third source of fluid of said valve cylinder.
 2. In a spray apparatus of the class described for mixing and spraying plural fluids; a fluid mixing valve as defined in claim 1 wherein said manual actuator affixed to said cylindrical valve piston comprises a handle connected to one end of said cylindrical valve piston by means of a pin and detent mechanism, so as to permit lifting and lowering of the handle in one plane and when in the lifted position, rotation of the handle transfers rotational movement to the cylindrical valve piston to selectively position the ports of the cylindrical valve piston relative to the ports of the valve cylinder.
 3. In a spray apparatus of the class described a fluid control mixing valve as defined in claim 1, having a cylindrical valve piston with the two inlet ports on the periphery thereof, a sleeve surrounding one portion of said cylindrical valve piston, a groove on the outer peripheral surface of said sleeve to transfer the third fluid, connecting passages from said sleeve groove to each of said cylindrical valve piston ports, thus permitting a single solvent third fluid inlet to transfer solvent for cleaning purposes to both material inlet ports of said cylindrical valve piston.
 4. A spray apparatus for mixing and spraying plural fluids containing the fluid mixing valve and actuating means as described in claim 1 which consists of a spray apparatus body to contain said mixing valve, a grip handle disposed beneath and connected to said body, trigger mechanism on said grip handle for releaseably locking said mixing valve to prevent or permit rotation of said cylindrical valve piston, a dispensing nozzle removeably attached to the outlet end portion of said cylindrical valve piston to dispense mixed fluids, and suitable adapters and connecting lines to carry the fluids to the spray apparatus. 